Exemplary embodiments of the invention relate to a rotary wing aircraft, and more particularly, to a swashplate for controlling a rotor assembly of a rotary wing aircraft.
Control of a rotary wing aircraft is affected by varying the pitch of the rotor blades individually as the rotor rotates and by varying the pitch of all of the blades together. These are known respectively as cyclic and collective pitch control. Blade pitch control of a rotary wing aircraft is typically achieved through a swashplate assembly which transfers the motion of non-rotating servo-driven control members within to the rotating members.
The swashplate assembly is typically concentrically mounted about a rotor shaft. The swashplate assembly includes two rings connected by a series of bearings with one ring connected to the airframe (stationary), and the other ring connected to the rotor hub (rotating). The rotating ring is connected to the rotor hub through a pivoted link device typically referred to as “scissors”, with the static ring similarly connected to the airframe. The rotating swash plate rotates relative the stationary swash plate. Apart from rotary motion, the stationary and rotating swash plate otherwise move as a unitary component. Collective control is achieved by translating the swash plate assembly up and down with respect to the rotor shaft and cyclic control is achieved by tilting the swash plate relative to the rotor shaft.
The stationary ring is typically mounted about the rotor shaft through a spherical ball joint that allows for tilt of the swash plate assembly, with the rotor shaft allowing translation of the swash plate assembly along the axis.